<template>
  <div id="aCoursesList" class="bg-fa of">
    <!-- /课程列表 开始 -->
    <section class="container">
      <header class="comm-title">
        <h2 class="fl tac">
          <span class="c-333">全部课程</span>
        </h2>
      </header>
      <section class="c-sort-box">
        <section class="c-s-dl">
          <dl>
            <dt>
              <span class="c-999 fsize14">课程类别</span>
            </dt>
            <dd class="c-s-dl-li">
              <ul class="clearfix">
                <li>
                  <a title="全部" href="#">全部</a>
                </li>
                <li v-for="(onesubject,index) in subjectNestedList" :key="index" 
                @click="chooseOneSub(onesubject.id,index)" :class="{active:index==oneIndex}">
                  <a :title="onesubject.title" href="#">{{onesubject.title}}</a>
                </li>
              </ul>
            </dd>
          </dl>
          <dl>
            <dt>
              <span class="c-999 fsize14"></span>
            </dt>
            <dd class="c-s-dl-li">
              <ul class="clearfix">
                <li v-for="(twosubject,index) in subSubjectList" :key="index"
                @click="chooseTwoSub(twosubject.id,index)" :class="{active:index==twoIndex}">
                  <a :title="twosubject.title" href="#">{{twosubject.title}}</a>
                </li>
              </ul>
            </dd>
          </dl>
          <div class="clear"></div>
        </section>
        <div class="js-wrap">
          <section class="fr">
            <span class="c-ccc">
              <i class="c-master f-fM">1</i>/
              <i class="c-666 f-fM">1</i>
            </span>
          </section>
          <section class="fl">
            <ol class="js-tap clearfix">
              <li :class="{'current bg-orange':buyCountSort!=''}">
                <a title="销量" href="javascript:void(0);" @click="searchBuyCount()">销量
                <span :class="{hide:buyCountSort==''}">↓</span>
                </a>
              </li>
              <li :class="{'current bg-orange':gmtCreateSort!=''}">
                <a title="最新" href="javascript:void(0);" @click="searchGmtCreate()">最新
                <span :class="{hide:gmtCreateSort==''}">↓</span>
                </a>
              </li>
              <li :class="{'current bg-orange':priceSort!=''}">
                <a title="价格" href="javascript:void(0);" @click="searchPrice()">价格&nbsp;
                  <span :class="{hide:priceSort==''}">↓</span>
                </a>
              </li>
            </ol>
          </section>
        </div>
        <div class="mt40">
          <!-- /无数据提示 开始-->
          <section class="no-data-wrap" v-if="data.total == 0">
            <em class="icon30 no-data-ico">&nbsp;</em>
            <span class="c-666 fsize14 ml10 vam">没有相关数据，小编正在努力整理中...</span>
          </section>
          <!-- /无数据提示 结束-->
          <article class="comm-course-list" v-if="data.total > 0">
            <ul class="of" id="bna">
              <li v-for="course in data.courseList" :key="course.id">
                <div class="cc-l-wrap">
                  <section class="course-img">
                    <img :src="course.cover" class="img-responsive" :alt="course.title">
                    <div class="cc-mask">
                      <a :href="'/course/'+course.id" title="course.title" class="comm-btn c-btn-1">开始学习</a>
                    </div>
                  </section>
                  <h3 class="hLh30 txtOf mt10">
                    <a :href="'/course/'+course.id" :title="course.title" class="course-title fsize18 c-333">{{course.title}}</a>
                  </h3>
                  <section class="mt10 hLh20 of">
                    <span class="fr jgTag bg-green" v-if="Number(course.price) == 0">
                      <i class="c-fff fsize12 f-fA">免费</i>
                    </span>
                    <span class="fl jgAttr c-ccc f-fA">
                      <i class="c-999 f-fA">9634人学习</i>
                      |
                      <i class="c-999 f-fA">9634评论</i>
                    </span>
                  </section>
                </div>
              </li>
            </ul>
            <div class="clear"></div>
          </article>
        </div>
        <!-- 公共分页 开始 -->
        <div>
          <div class="paging">
            <!-- undisable这个class是否存在，取决于数据属性hasPrevious -->
            <a
              :class="{undisable: !data.hasPrevious}"
              href="#"
              title="首页"
              @click.prevent="gotoPage(1)">首</a>
            <a
              :class="{undisable: !data.hasPrevious}"
              href="#"
              title="前一页"
              @click.prevent="gotoPage(data.current-1)">&lt;</a>
            <a
              v-for="page in data.pages"
              :key="page"
              :class="{current: data.current == page, undisable: data.current == page}"
              :title="'第'+page+'页'"
              href="#"
              @click.prevent="gotoPage(page)">{{ page }}</a>
            <a
              :class="{undisable: !data.hasNext}"
              href="#"
              title="后一页"
              @click.prevent="gotoPage(data.current+1)">&gt;</a>
            <a
              :class="{undisable: !data.hasNext}"
              href="#"
              title="末页"
              @click.prevent="gotoPage(data.pages)">末</a>
            <div class="clear"/>
          </div>
        </div>
        <!-- 公共分页 结束 -->
      </section>
    </section>
    <!-- /课程列表 结束 -->
  </div>
</template>
<script>
import courseApi from '@/api/course'
import subjectApi from '@/api/subject'

export default {
  data(){
    return {
      page:1,  //当前分页
      data:{},  //课程列表及其他分页参数
      subjectNestedList: [], // 一级分类列表
      subSubjectList: [], // 二级分类列表
      searchObj: {}, // 查询表单对象
      oneIndex:-1,  //若一级分类索引和该索引一致，表示该分类被选中
      twoIndex:-1,  //若二级分类索引和该索引一致，表示该分类被选中
      //标识是否按价格排序 
      buyCountSort:"",
      //标识是否按最新排序
      gmtCreateSort:"",
      //标识是否按购买数排序
      priceSort:""
    }
  },
  created(){
    //初始化课程列表
    this.initCoursePageList() 
    //初始化一级分类
    this.initOneSubject()
  },
  methods:{
    initCoursePageList(){ //初始化课程列表
      this.gotoPage(1)
    },
    initOneSubject(){ //初始化一级分类列表
      subjectApi.getAllSubject()
      .then(response => {
        this.subjectNestedList = response.data.data.list
      })
    },
    gotoPage(page){  //跳转到指定分页
      //调用后端接口获取课程列表
      courseApi.getCoursePageList(page,8,this.searchObj)
      .then(response => {
        this.data = response.data.data
      })
    },
    chooseOneSub(onesubjectId,index){ //选中一级分类
      //清空二级分类列表
      this.subSubjectList = []
      //清空二级分类标识
      this.twoIndex = -1
      //清空查询条件中二级分类ID
      this.searchObj.subjectId = ''

      //为选中的一级分类添加样式
      this.oneIndex = index

      //查询一级分类课程
        //根据一级分类ID，查询后端数据库一级分类下的所有课程
      this.searchObj.subjectParentId = onesubjectId

      this.gotoPage(1)

      //查询二级分类并显示
        //根据选中的一级分类ID，遍历一级分类列表，若匹配，将其二级分类列表赋值给当前二级分类列表的变量
      for(let i=0;i<this.subjectNestedList.length;i++){
        if(onesubjectId == this.subjectNestedList[i].id){
          this.subSubjectList = this.subjectNestedList[i].children
        }
      }

    },
    chooseTwoSub(id,index){
      //选中二级分类
      this.twoIndex = index
      //根据一二级分类ID查询课程
      this.searchObj.subjectId = id

      this.gotoPage(1)
    },

    //点击二级分类，查询数据
    searchTwo(subjectId, index) {
      this.twoIndex = index
      this.searchObj.subjectId = subjectId;
      this.gotoPage(this.page)
    },
    //购买量查询
    searchBuyCount() {
      this.buyCountSort = "1";
      this.gmtCreateSort = "";
      this.priceSort = "";
      this.searchObj.priceSort = this.priceSort;
      this.searchObj.buyCountSort = this.buyCountSort;
      this.searchObj.gmtCreateSort = this.gmtCreateSort;

      this.gotoPage(1)
    },
    //更新时间查询
    searchGmtCreate() {
      //debugger
      this.buyCountSort = "";
      this.gmtCreateSort = "1";
      this.priceSort = "";

      this.searchObj.buyCountSort = this.buyCountSort;
      this.searchObj.gmtCreateSort = this.gmtCreateSort;
      this.searchObj.priceSort = this.priceSort;

      this.gotoPage(1)
    },
    //价格查询
    searchPrice() {
      this.buyCountSort = "";
      this.gmtCreateSort = "";
      this.priceSort = "1";

      this.searchObj.buyCountSort = this.buyCountSort;
      this.searchObj.priceSort = this.priceSort;
      this.searchObj.gmtCreateSort = this.gmtCreateSort;

      this.gotoPage(1)
    }
  }
};
</script>
<style scoped>
  .active {
    background: #bdbdbd;
  }
  .hide {
    display: none;
  }
  .show {
    display: block;
  }
</style>